The present invention relates to the art of computer driven printers and, more particularly, to large format color ink jet printers. Printers of this type have a printhead carriage which is mounted for reciprocal movement on the printer in a direction orthogonal to the direction of movement through the printer of the paper or other medium on which printing is to take place. The printer carriage of a color printer has at least one, and typically four, six or even more removable piezo-electric or thermal ink jet printheads, frequently referred to as pens, mounted thereon. Each pen may include a self contained supply of ink which, for large scale printers, is generally inadequate due to the large volumes of ink which are required as compared with the ink supply requirements of smaller desk top printers. Consequently, various means have been proposed for continuously or periodically refilling the carriage-borne pens with ink. These systems fall into two categories. The first comprises offboard or off-axis ink reservoirs which are continuously connected to the carriage-borne or onboard pens by flexible tubes. The second comprises a xe2x80x9ctake a gulpxe2x80x9d system in which the printhead carriage is periodically moved to one end of its path of travel where it is then connected with off-axis ink reservoirs to fill the onboard pens.
Since the ink delivery tubes connected from offboard reservoirs to onboard pens continually flex, leakage and breakage of the ink supply tubes may be experienced. A reliable ink delivery system and guides for routing the ink delivery tubes from offboard ink supplies to the printhead carriage to minimize flexing, wear and damage of the ink tubes is shown in U.S. Pat. No. 6,206,512 B1 issued Mar. 27, 2001 to Gasso, et al. and owned by the assignee of the present invention, that disclosure being incorporated herein by reference. The moveable pen carriage shown in that patent has a number of installation stalls into which pens containing different colors of ink are inserted. These pens each have a downwardly opening fill port which slidably mates to establish fluid communication with an upwardly directed ink supply tube on the carriage and the pens are held in place in stalls in the carriage by a pivotal latch cover.
The use of replaceable carriage borne pens having upwardly opening fill ports to minimize ink dripping and leakage is desirable but the use of pens with upwardly opening fill ports requires the fluid connections of the ink supply tubes to the pens to be routed above the pens through the latch cover. The ink tubes are therefore necessarily twisted and flexed whenever the cover is pivotally opened or closed when installing and removing pens from their individual stalls thereby subjecting the tubes and connections to wear failure and eventual leakage. The present invention is directed to reliably and inexpensively solving this problem.
The present invention provides an inkjet pen carriage having a base defining a plurality of pen stalls, a pen cover pivotally attached to said base, said cover including fluid tubes having a length extending between pivotal connections of said cover to said base, said length extending generally parallel to an axis of pivotal connection of said cover to said base and at least one tube being spaced from said axis to permit twisting of said tubes in said length of said tubes about said axis, said tubes terminating in fluid delivery outlets for said pen stalls.
The present invention further provides an inkjet printer including a moveable carriage, at least one inkjet pen having an upwardly directed fluid inlet mounted on said carriage, a fluid reservoir remote from said pen and a fluid delivery tube for connecting said reservoir to said pen, said carriage including a base and a pen cover pivotally attached to said base, said tube having a length extending between pivotal connections of said cover to said base, said length extending generally parallel to an axis of pivotal connection of said cover to said base to permit twisting of said length of tube between said connections, said cover including a fluid delivery passageway having a fluid delivery outlet slidably connected in fluid delivery relationship with said pen inlet.